Forgotten about for 15 years

Tenants moved out of my parents’ rental house after 15 years and I found this jade plant sitting in the backyard with some old stuff. My mom had left it there years ago when it was just a tiny plant. The tenant said they didn’t have any plants and no plans for it, so my mom assumed it must’ve gotten left behind during their move years ago. Now it’s huge and still somehow living in the same pot. They also said they never watered it. Southern California climate for context. Coke can included to show trunk size